6ef840f3cf
* Reduces checkstyle errors in naked-objects * Reduces checkstyle errors in null-object * Reduces checkstyle errors in object-mother * Reduces checkstyle errors in object-pool * Reduces checkstyle errors in observer * Reduces checkstyle errors in queue-load-leveling
67 lines
1.8 KiB
Java
67 lines
1.8 KiB
Java
/*
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* The MIT License
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* Copyright © 2014-2019 Ilkka Seppälä
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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package com.iluwatar.nullobject;
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/**
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* Null Object implementation for binary tree node.
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*
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* <p>Implemented as Singleton, since all the NullNodes are the same.
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*/
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public final class NullNode implements Node {
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private static NullNode instance = new NullNode();
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private NullNode() {
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}
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public static NullNode getInstance() {
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return instance;
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}
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@Override
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public int getTreeSize() {
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return 0;
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}
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@Override
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public Node getLeft() {
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return null;
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}
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@Override
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public Node getRight() {
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return null;
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}
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@Override
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public String getName() {
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return null;
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}
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@Override
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public void walk() {
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// Do nothing
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}
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}
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